1. Field of the Invention
The present invention relates to the decoding of a video, and more particularly, to a filtering apparatus, method, and medium for a multi-format codec (coder and decoder), which can be commonly used for various video compression formats to implement the multi-format codec.
2. Description of the Related Art
There are various video compression algorithms, i.e., video compression formats such as Windows® Media Video 9 (WMV-9) codec and H.264 codec (a digital video codec industry standard established by Video Coding Experts Group and Moving Pictures Expert Group). A detailed encoding/decoding algorithm varies from format to format. In general, a decoding algorithm suitable for a particular video compression format extracts a motion vector from a received bitstream, generates a current prediction frame using a reference frame that has been already reconstructed and the extracted motion vector, and reconstructs a current frame using the generated current prediction frame and residual data included in the bitstream.
A block boundary is visually distinguished in a digital video reproduced through decoding. This is called a blocking happening. A loop filter is used to reduce or remove the blocking happening. In other words, the loop filter is inserted into a decoding loop of a codec (coder and decoder) for deblocking. Moreover, in a currently required multi-codec decoder, i.e., a decoder supporting the video compression formats WMV-9 and H.264, developing a method for implementing a separate filtering process for each of the video compression formats increases the time and cost required for the development. Thus, there is a need to reduce the time and cost required for the development through filtering common to various video compression formats.